Sport players, such as baseball players, tennis players, etc., would like to have the opportunity for more frequent practice in developing a proper stroke with use of a bat or a racket, etc. Since hitting a baseball results in the baseball traveling an extended distance, baseball players often go to a facility such as a baseball practice range to practice their stroke, which is inconvenient for reasons such as the time required to get there, delays due to increased overcrowding, and the cost of using the facility.
Various devices have been developed which hold the baseball at a predetermined initial position to be hit by a baseball bat. For efficient practicing of swings, it is desired that the user is able to practice continuously. It is further desired that the user is able to acquire a good sense of timing for hitting the ball. It is further desired that those functionalities be achieved with a simple structure to reduce cost and improve reliability.